Electrical indicating instrument.



R. C. LANPHIER. ELBUTBIUAL INDIUATII NSTRUMBNT. Arrmouxon FILED 852121. 19o?.

- t 910,549. Patented Jan i909.

,j @gaf it einem a instruments `ol" the same current with an alternating current.

forces.

ROBERT C. LAI'BI, SFEINGFIELQ,

ILL-issn., Ansinnen To sANGAMo ELECT RIG ` COMPANYQOF SPRINGFIELD, ILLINOIS, A CORPORATION OF ILLINOIS.

ELEGTBICAL INDICATING INSTRUIIENT.

may concern:

thatI, ROBERT C. LANPHIER, acitizenfof the United States, residing at the county of Sangainon, State of I inois, haveinvented certain new and useful Improvements in Electrical Indicatinglnstruments, of which the following is a specification, reference being had to the accompanying drawings.

V My invention rel tes to electrical measuringinstruments such as those ordinarily usedxforindicating momentary values `of volts, .amperes, or watts in a circuit.

this class, it has been found practical to make direct current ammeters and volt meters whose indicating scales have uniform divisions over any desired range. A common `and well-known type of such instruments "is the so-called DArsonval per manent magnet type. This type of indicating instrument, however, cannot be used Many forms of alternating cprrent indicating instruments have been devised, however, but no one of them, so far as I am aware, has been of the mercury motor. meter type. A device of the mercury' meter meter type, by making appropriate: changes and additions, ofcourse, can be made to operate as a watt or ammeter for a direct current, becausethe energizing field may be energized by a shunt circuit,

yBeit known ,passing the load'current th rough the mercury chamber and across the disk armature. To apply such a device with the 'ordinary form o armature, however, to an alternating current, would 've rise to difficulties, makit im ossiblia to use a scale of substanti y u arm divisions, except by the use of cams, or more or less complicated mechanisms for changing the 'movement of the index finger from the actual ratio of deflective The reason for this is that, in such a device in use in an alternating 'current, it

`would lbe practically necessary to pass `through the -moying element or armature hich passes ,through the main or seriesy winding ofthe device, or to induce in the moving element a magnetism varying practicallyin 4proportion to the current. It would result from this that the operation of such a-device, as is well known, would follow the lawof squares-that is to say, the torque or turning momentupon the shaft would increase with the square ofthe energizing current, of approximately thereto.

Specification' of Lettera Patent. Application filed September 21, 1907. Serial No. 398,997.

ments the divisions Instead, therefore, of of deflection, Which would e the case if the torque varied directly proportion with the current, it results that with such instru of the scale must increase rapidly unless some cam or other a uniformjscaler nieuwe .19.11.26, ieee; I;

mechanism is employed between the turning element and the indicating needle to compensate for this. that a sufficiently wide scale cannot be 4ob-y tained within any convenient size of scale.

It is the object of my invention',

of increase proportional to the volts or ainfperes upon a circuit may be used. Generally speaking, I accomplish this by vconstructing an instrument which is of the mercury motor meter type, the armature, however, being sq shaped that its successive radii diminish in in such relation to the driving power roduced by the combinedcurrent and iiel effeet that the torque of said current and field upon said armature shall increase directly as the 'current increases, thereby eliminating the o eration of the normal law of squares in the eilection of the indicating finger and making possible, as has been said, a practically uniform scale.

I accomplish these objects by the means Vshown in the drawings and hereinafter described.

That which I believe to be new will be set forth in the claims.

In the drawings :-Figure 1 is a side eleva.- tion of my device, partially in vertical secition, and showi a part of the scale re moved to show the parts within. Fig. 2`s a top or plan view of the bottom part vof the case, the top part with `its contained and supported devices being removed. Fig. 3 is a diagramrn atic illustration omy device ap plied with 'a shunt'.4 Fig. 4 is a diagramamatic view illustrating my invention,A showing its application in an alternating current volt meter.

Referring to the drawings, 5 indicates a casing formed ofv insulating material and oon-- sisting of .an upp r and a lower part, 5* and 5", respectively.

It follows again from this length as said disk rotates h therefore, to produce an indxcatnig instrument, ri#` ut IDE .plate of conducting metal,

er, and secured upon the spindle 12 near its- 6 indicates a shallow circular chamber in the casing 5 adapted to contain mercury and to contain the armature hereinafter described.

7-7 indicate contacts which preferably enter the chamber from the sides diametrically opposite one another.

8 8 indicate laminated pole pieces of an electro-magnet which are mounted in the bottom member 5b of the casing and project {,)hrough the same to the bottom of the cham- 9 indicates the main circuit with translating devices 10.

1 1 indicates the field windings of the magnet which are connected in thelcircuit in series with the contacts 7.

12 indicates a spindle which is journaled in suitable bearings 131.4-15, and projects upward through the casing. The bearing 13 is mounted in any suitable manner in the other parts of the casing of the meter, which are all omitted for clearness of illustration and-may be of an well-known form and type and will be readi y understood.

16 indicates a pin which is secured rigidly to the bearin 13 and projects downward beside the spin le 12.

17 indicates a coiled spring, one end of which is secured to the spindle 12 and the other end to the pin 16.

18 indicates a pointer which is secured to the spindle and projects horizontally therefrom, being bent over at its outer end 19 to traverse an arc-sha ed scale 2() which is secured to the casing oi) the meter in any ap` propriate manner. 's has been said, the casing and other parts are of any well-known 'form of description, and, as they will be readily understood and form no part of my present invention, they are omitted for the sake of clearness of illustration.

21 indicates an armature formed of a thin referably copcWer end so asto rotate in the chamber 6. As is best shown in Fi 2, the armature is preferabl symmetrica upon both sides of the spin le, in order that the current from the contacts,--which, as has been said, are preferably located diametrically opposite each other,-may pass across the entire d1- ameter of the armature and render effective both magnetic fields. Asis best shown in Fi 2, the edge of the armature u on each sia of the spindle, and forward in t e direction of rotation indicated by arrows in Fig. 2 is straight from the edge to a oint near the spindle, while the other edl e o the armature is curved in substantial y an involute curve Whose successive radii away from the straight edge diminish in length in such relation to the driving .power roduced by the combined current and field) effect that the eective torque of said current and field upon said armature shall increase directly as the current increases.

22 indicates a return plate of magnetic material which is embedded or otherwise fixed in the u per member' 5 of the casing 5.

30 inf icates a stop in said chamber adapted to limit the rotation of the armature.

The operation of the device is as follows :w The parts are so set that when there is no current passing and the pointer is consequently at zero on the scale, the disk will be in the position shown in Fi 2. ln this position it is obvious that t e armature will have its, maximum length subjected to the maximum area of fields from the adjacent poles of the magnet, and u on the passing of the current, the said dis c will be turned against the action of the spring 17, moving the pointer over the scale in pro ortion to the amount of the current. As t e current increases to increase the turning of the disk and to cause the 'further moving of the pointer upon the scale, it will be seen that oth the eective clement of the armature through which the load current is assing is decreasing, and at the same time t e area of the magnetic field acting upon such armature is also decreasing. By this means, the desired resultant of proportional scale deflection may be obtained and the scale 20 may be made with substantially eq'ual divisions.

Fig. 3 illustrates my invention as operated with a shunt on an alternating current similar to the ordinary use of shunts in direct current ammeters, showing the entire current carried through the series field windin s and only the armature current shunted. n this case, 23 indicates a resistance shunt and 24 indicates the circuit from the resistance shunt through the contacts and armaure. In all other respects, the parts are simi arly nurlnbered to the corresponding parts shown in i 1.

lt igs obvious that in case it should be desired to apply this indicating instrument upon a direct current, the entire device, both the armature and series field windings, could be shunted, asin that casethere would be no inductive efl'ect from the series coil to cause error.

In Fig. 4, l have shown my mechanism as applied to an alternating current volt meter. In this diagrammatic view, 5 indicates the casing, 6 the chamber, 7 the contacts, 8 the laminated pole pieces, 9 the main circuit, 10 the translating devices, 12 the spindle, and 21 the armature, the parts being numbered the same as corresponding parts in Fig. 1. 25 indicates a transformer, of which the primary 26 consists of a large number of turns of ne Wire connected across the circuit 9, and the secondary 27 of one or two turns of large wire so constructed as to furnish acurrent of very low potential but of some fifteen to twenty amperes to the armature. 28 indientes the circuit from tHe low potential 3. In an electrical measuring instrument secondary of the transformer, an 29 the rovided with a mercury chamber, the comeld windings which are in series with the' contacts 7.

I have described my invention as applied to alternating current measuring instrumentarl and it is the principal object of my invention to provide for spch a. measuring instrument for alternating currents. It will he obvious however, that m measuring instrument 1s' equally applicab e to direct current measurement, and' I therefore do not confine its application to its use with alternatlng currents.

What I claim-as my invention and desire 10 secureby Letters Patent is :d

1. In an electrical indicating instrument, the combination ywith a chamber adapted to contain a conducting iiuid, contacts entering said chamber, field poles, ield windings in serlxes with said contatts, a spindle, and indicating devices operatively connected therewith, of an' arnfature secured to. said spindle 1n said chambe and so shaped that its suc- Cesslve radii diminish in length wherebythe eIfective path or the current passing through said armature decreases in length as the curre'nt increases.

In an electrical indicating instrument, the combination with a chamber adapted to contain a conducting fluid, contacts entering said cha'mber, field poles, field .windings in series-with said contacts, a s indie, a spring connected to said spindle an adapted to rcsist the turning thereof, .and indicating de vices operatively connected'with said spindle,

of an armature secured to said spindle in said chamber nd so. shaped that its successive radii dim mishin length whereby the effective path. of the current passing throu h said armature decreases in lengtn as t e current increases.

ination o'I' a eld magnet, a swinging metallic vane immersed in the mercury, and contacts adapted to carry the current to and from said vane, the vane being so shaped that its successive radii diminish in length whereby the effective path of the current passing through said vane decreases in length as said current increases.

4. In an electrical measuring instrument,

the` combination with a field nianet, of a vane pivoted to swing in the iied of said magnet, and means for conducting current through said vane, said vane being so shaped that its successive radii progressively diminish in length whereby the eil'ective path of the current passing through said vane decreases in length as the current increases..

5. In an electrical measuring instrument, the combination with a iield ma et, of a vane pivoted to swing in the fie d of said magnet, and means for conducting a current through said vane, said vane having one of its edges so shaped that the successive radii progressively diminish in length as the vane rotates', whereby the effective path of the current passing through said vane decreases in len th as the current increases.

6. n an electrical measuring instrument, the combination with a field magnet, of a vane connected in series with said magnet and mounted to swing in the field thereof, said Vane being so sha ed that the successive radii progressively diminish in length whereby the effective path of the current passing through said vane decreases in length as the current increases.

f ROBERT C. LANIIIIER. Witnesses:

BERTHA O. LANPHIER, MARGARET E. CoNLIsK. 

